docs: def __get_keys_map(self, bundleId, languageId, fallback=False):
          """Returns key-value pairs for the specified language.
          If fallback is ``True``, source language value is used if translated
          value is not available.
          """
          return self.__get_language_data(bundleId=bundleId,
              languageId=languageId, fallback=fallback)